I think it's worth noting that Clearwire and Google did a pretty darn awful way of handling email accounts: Clearwire used basically Google Apps (now Google Workplace) for all of their customer's accounts. It meant that yeah, all their customers got their @clear.com addresses with a Gmail client instead of something likely far worse.

...But when Clearwire started to go downhill, they just... shut it off. There was no way to migrate over to a regular Gmail account, Google obviously had no bespoke method for people to keep using their @clear.com addresses. People just straight up lost their online identity. I had a customer at the time who literally just didn't understand why she couldn't log into her email anymore, she hadn't understood the notices Clearwire sent out.

In comparison, people with aol.com and earthlink.net accounts are still out there. Heck, peoplepc.com email is still out there! I'd argue if you're going to hand out consumer email addresses, you ought to have a plan to ensure they effectively never lose their email addresses. I am a little vexed that Google even let them do what they did, and neither Clear nor Google had a real migration plan when they ended it.

"...starting April 15, 2015, Clearwire will no longer support your CLEAR Email/Clearwire Email services. After that date you will no longer be able to send or receive emails, nor will you have access to any stored emails. This service deactivation affects all CLEAR Email/Clearwire Email accounts. Other applications that come with your Clear Email/Clearwire Email are also impacted and will no longer be available including Google Talk/Hangouts, Google Drive and Google Calendar..."